In the time before digital computers could do graphics, photography was a film thing. Because light hitting undeveloped film or photo-print paper will expose it, undeveloped film and print papers have to be handled in a room without light a dark room. (A red light at the very reddest end of the visible light spectrum is used to provide some illumination in a photo darkroom.)

Exposed film and print papers are developed in chemical baths in the darkroom. Machines in the darkroom called enlargers are used to blow up or reduce the size (scaling) of photos for printing and to crop them for printing.

Optical filters can be used with the Enlargers to modify the appearance of photographs. Darkroom tricks can be used to superimpose part or all of one photo upon another for printing. Text or artwork can be superimposed upon a photograph too.

As sufficient computer resources were developed and deployed to enable digital image manipulation and editing, software was developed to do just that. Thus, today everything from snapping photos digitally, to editing photos, to printing photos can be done digitally -- digital cameras for snapping the photographs, digital computers and software for editing the photos, and digital (computer) printers for making photo prints.

In addition to the classic darkened room, today there also is a computerized virtual darkroom, the digital darkroom. In essence, the digital darkroom is the computer, accessories, and software used (a) to download photographs from a digital camera or scan film or print photographs into a computer, (b) process, manipulate, and edit the photographs, and (C) print the processed photographs.

Cropping and scaling (resizing) photos, along with adjusting the brightness and contrast of them, are among the most basic elements of photo editing. In this hands-on tutorial, you will learn how to use The GIMP's powerful cropping, scaling, brightness, and contrast tools by editing a photograph in our digital darkroom.

You can later apply the basic skills, elements, and principles that you learn in this tutorial to edit and manipulate photos, clipart, scanned images and other digital graphics. You also can use the GIMP to design and create all sorts of stunning computer graphics and images from scratch. However, today's tutorial focuses on editing already existing images with the GIMP.

Originally, GIMP was a Linux/UNIX program. However, it has been ported to the Microsoft Windows platform -- that effectively makes GIMP a cross-platform (XP) program. There appear to be some Mac versions of the GIMP now also.

The GIMP and Adobe Photoshop are comparable, digital-darkroom, software products as to features, functions, and usability -- other than some advanced professional and prepress stuff in Photoshop. The basic photograph and image cropping, scaling, color-brightness adjustment, and color-contrast adjustment operations covered in today's tutorial are just as easily done and well-done with the GIMP as with Photoshop.

Moreover, GIMP is free and Photoshop costs $699. Because GIMP is an excellent, pixel-based, image manipulation and editing program and because of licensing and pricing issues, we chose to use the GIMP rather than Photoshop in our digital darkroom. More about the GIMP and Photoshop further on in this article.

Overview of Today's GIMP Tutorial

In today's tutorial, let's edit one of the photos from the Goose series used in the GIMP Overview article.

The purpose of today's tutorial is:

(a) to introduce people that never have used an image or photo-editing program to image-editing and photo-editing software basics,

(b) to introduce people that never have used The GIMP to GIMP basics,

(c) and to help Adobe Photoshop and Photoshop Elements users migrate to the GIMP.

Thus the focus of today's how-to article is on the basics of using GIMP's cropping, scaling, brightness adjustment, and contrast adjustment tools. You will learn how to use these tools by editing a digital photograph.

If you have a digital camera, the GIMP is an important tool that you should have in your digital darkroom. Please see About the Digital Darkroom in the right-hand sidebar.

The GIMP is included with many prominent GNU-Linux distributions. If you have a major GNU-Linux distribution such as Mandrake or SUSE, you likely already have the GIMP.

If you are an MS Windows user you might not already have the GIMP installed. The good news is that whichever of the above listed OSs you use; you can download and install the GIMP at no charge to you. Download links are in the Resources section at the end of this tutorial on page 4.

Figure 1, below, shows the GIMP version 1.3 opened in SUSE Linux Professional 9.0 and the KDE desktop. The Geese picture to be edited is in the upper right of the screen shot.

Figure 1. Screen shot of GIMP version 1.3 running on SUSE Linux 9.0 and the KDE desktop for Linux. The crop tool has been used to place a crop box around the area that will remain after cropping. Please see text for an explanation. (Geese photo by Mike Angelo)

All the figures in today's tutorial were made with the GIMP version 1.3 opened in SUSE Linux Professional 9.0 and the KDE desktop. Screen shots were made using the GIMP's screen shot feature.

The next major GIMP release will be GIMP 2.0. The current end-user version is GIMP 1.2.5. In between those two versions is GIMP 1.3.x, the pre-2.0 developers' version.

Since this tutorial is based upon GIMP 1.3, it should also be applicable to GIMP 2.0 when it is released. The tools used in today's tutorial also are in GIMP 1.2.x. Thus, this tutorial also is applicable to GIMP 1.2.x.

The Hands-On GIMP Tutorial

Getting Started

There is no one, single, way to go about taking pictures or editing them. There are different tools that you can use, even within one photo-editing program. Moreover, there are different ways to use those tools. The way this tutorial shows you how to do your digital-darkroom work is just one of many approaches.

This tutorial shows you the mechanics of basic photograph and image editing with the GIMP. Unfortunately, photograph and image artistry is beyond the scope of today's tutorial.

However, it is much more the photo artistry than the mechanics that makes great photos and graphics. If you are a college student, take a studio (art) course to learn artistry basics. That is a real hands-on studio course not some wimpy art appreciation course. Or if you are not a college student, take a real, hands-on, studio course at your local community college.